Improved trestle-bridge



` MWC) HHHHHHHH uuuuuuuuj i NITE@ STATES irren'r Ormes,

ANDREW Drinnen, or .rurnnson 'New Jansma Vl MPROVED TELSTLEBREDGE.

Specification forming part of -Letters Patent No. 45,530, dated July 4, 1865.

To all whom it may' concern:

Beit known that I, ANDREW DnaRoi/r, of Paterson, in the eounty'of Passaic and State of New Jersey, have invented new and useful Improvementsin Trestles forridges, Src.; and I do hereby declare that the followingis a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specificatione The present invention consists, first, insecuring the cap ofthe trestle to and upon the legs or standards ot' the same by means of a Wedge-shaped piece driven into and up through `the cap from its underside and bearn g against the upper portion of 'the leg therein, tightly and firmly holding the. cap and leg together and in the proper position; second, in the use ofladjustable feet for the legsot' a trestle, which are so arranged and attached thereto as to adjust themselvesto the inequalitiesfof the surface uponwhich they may rest; third,in attachingto, and at or near the lower end ot',

the'trestle-legs one or more horizontal radiating or projecting rcd`s`,.so that by surrounding or completely covering the same with any com` monheavy materials-V-snch as large stones,

8va-fthe legs are prevented from being affectedby the currents ot' the stream in which they may be placed and other well-known causes,

and thusmade 'and preserved more iirm'and rigid therein. t

In the accompanying plate of drawingsmy improvements are represented as applied to a bridge,Figure1 beingavertical section-through one trestle thereof; Fig.2, a plan or top view of one section of a bridge between two trestles 5 Fig. 3, a detail view of a trestle-fcot and Figs.

4 and 5, other detail views, to be hereinafter tures, through which the upper ends of the legs are passed, as described, a wedge-shaped. piece, e, is driven from the under side thereof, and brought toa tight bearing thereon between the leg and cap-piece, firmly and securely fast-` ening and holding the two together, or the cap. upon its legs.

d d d, Src., representa series of longitudinal beams or balks running from trestle to trestle,

placed parallel to each other at short distances apart, and over and across which the planking f f, constituting the road-bed of the bridge, is laid, the balks and planking being secured to each other and to the trestles in any proper mnner.

g represents the trestle-i'eet, hung upon a Y short shaft, h, of the lower end 'of the legs, and turning upon the same, the legs being cut away, as seen in detail View, Fig. S, at l', so as to allow the feet to incline toward them, and thereby conform to `any unevenness in the surtaee upon which they may rest. feet may-be made of various shapes and sizes, according to the contour and nature of the ground upon which they are torest, such as, for instance, of aat'or disk shape, or with two cross arms orpieces.

` The trestles, constructed and'arranged as above described, whendcsired-to bridge `a stream, are sunk, oneat'ter another, and at desired distances apart, in the water until they rest upon the bottom thereowhen the balks and planking are then laid across the same, as above described; or,iu lieu ot' yfirst fastening the parts composing the trestles together before 'they are placed in the stream, each leg can be inserted by itself and then its cap attached theretol by the wedge-shaped pieces, as before described, and vthe t remainder yof the bridge fastened thereon in any proper manner.

It' any trestle should settle, or either one of its legs, vthus causing the road-bed to be uneven,

by my improvements it is easily obviated, as it is only necessary that the wedges of such tres tle or ot its leg should he rst loosened, and the cap-piece can then be raised to the proper level by any suitable lever arrangement, when' it is again fastened by setting the wedge as before, the advantages of which are evident.

In case the current of the stream that it is intended to bridge is strong or its waters deep The trestle4 a i n.530

orfdepth of the stream, and retain and hold" Y the legs firmly upon the bottoni thereof.

From the above description it is evident that my improvements in trestles for bridges render the bridge exceedingly simple and easy to be put together, as well as readily adjustable to any and all inequalities in and the nature of the bottom ofthe river that it is intended to bridge, the great advantage and importance -of which, in the erection of bridges to be used for military purposes, are evident. yBridges with my improved trestle, it may be here remarked as one evidence of its utility and practicability, and of its especial adaptation to military purposes, were constructed and erected by ine during the siege of Suffolk, Virginia, in April, 1863, and were there subjected to the severest tests with complete success, and were so certified to and strongly recommended by the commanding general, BrigadierGeneral George W. Getty, at that place; and it is evident that by driving the wedge into the cap from the under side thereof, as described, the greater th'e pressure upon the said cap from its upper side the tighter it is held by the wedge.

In lieu of using only one wedge, two or more may be used, if desired, but I deem one to be sufficient for all practical purposes; and, furtherrnore, the upper ends of the legs may be made of a wedge or tapering shape, if desired, although it is not necessary in order to hold the. cap thereon.

lAlthough I have described my improvet ments as particularly applicable to bridges for streams, they may as well be applied to the erection of staging, scaffolding, and to various other purposes, and therefore l do not intend limit myself tov their use for bridges as the only purpose to which they may be adapted.

The trestle may, if deemed necessary, be

braced by diagonal or cross braces fastened thereto in any proper man-ner.

I claim as new and desire to secure by Letters Patenten 1. Securing the cap-piece to the legs of a trestle to be used for bridges, Snc., by means of one or more wedge-shaped pieces driven into the same from the under side thereof, substantially as herein described.

2. The ad justable feet for the trestledegs, ar

ranged upon the same, substantially as herein described, and for the purposes specified.

' ANDW. DERROM. Witnesses: ALBERT W. BROWN, l

M. M. LIVINGSTON. 

